Anca Duta

Title : TiO2 Carbon derivatives composite photocatalyst for advanced and affordable wastewater treatment

Abstract:

The quest for novel efficient and affordable wastewater treatment processes brought photocatalysis into the focus. Highly efficient photocatalysis is based on wide band gap semiconductors that can depollute the wastewater even at low pollutant concentrations (at the ppm range) but above the discharge limit. Among the photocatalysts TiO2 is considered as one of the best candidates in the photocatalytic removal of pollutants during the advanced wastewater treatment, due to its stability in the aqueous media and its lack of toxicity. However, the wide band gap of TiO2 makes its activation possible only when using UV radiation. This is why, the challenge to develop up-scalable and affordable processes lead to the development of various solutions, based on composite layers that make the TiO2 component VIS-active; one of the recent attempts is to develop TiO2-graphene composite structures that support a better charge separation and reduce the electron-hole recombination in TiO2, thus better supporting the photocatalytic reaction mechanism. These composites are mostly reported to be obtained using sol-gel or hydrothermal synthesis, but this paper will report on thin composite layers of TiO2 and reduced graphene oxide (rGO) obtained by Spray Pyrolysis Deposition. The thin films are further tested in the methylene blue removal (according to the standard ISO 10678; 2010) and the results show that the process runs with promising efficiency when irradiated with solar radiation (irradiance higher then 600 W/m2). The influence of the synthesis conditions is investigated and the results show the optimum rGO content in the composite is of 1%. As the composite photocatalyst needs only solar radiation, the process is affordable and the results can be used also in developing self-cleaning coatings with similar composition.

Biography:

Dr. eng. Anca Duta (b. 1961) is Professor in the Transilvania University of Brasov, Romania and Ph.D. supervisor in Materials Science. Her activity focuses on solar energy materials used in solid state solar cells, solar-thermal coatings and in photocatalysis and is part of the H2020 group of experts on this topic(s). Her recent work on VIS-active photocatalytic materials focuses on the development of thin films, stable in water, with a structure similar to solid state solar cells that are efficient in organic pollutants removal from wastewater (e.g. TiO₂/CZTS or TiO₂/CIS). Further on, the development of VIS-active composite thin films included also graphene and graphene derivatives deposited on TiO₂ to get VIS-active materials for advanced wastewater treatment or for self-cleaning coatings.